I would never have guessed how such a minor part would make such a huge difference in the way the horn plays. I have a Bach Strad which was a grade school graduation present in 1979. The felts, springs, and all the valve hardware were the originals. I played it all through highschool, and through 3 years of college. Even played into my mid twenties, but work took over and I hung it up. My daughter starting playing trumpet about three years ago, and eventually wanted to use my Bach. The valves were so clunky sounding, and I realized after cleaning it up for her the valves did not quite line up in the up position. Why? Because the felt pads were incredibly worn, and no longer provided the adequate space to line the valves up with the slides. After replacing the pads and springs, the horn plays like a champ!! Cosmetically, it has seen better days. But my daughter absolutely loves the horn.